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Related papers: Geometric quantum discord for two-qubit X-states

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Quantum discord is a more general measure of quantum correlations than entanglement and has been proposed as a resource in certain quantum information processing tasks. The computation of discord is mostly confined to two-qubit systems for…

Quantum Physics · Physics 2015-06-05 Indrani Bose , Amit Kumar Pal

We examine the quantum correlations of spin pairs in the ground state of finite XY chains in a transverse field, by evaluating the quantum discord as well as other related entropic measures of quantum correlations. A brief review of the…

Quantum Physics · Physics 2013-12-16 N. Canosa , L. Ciliberti , R. Rossignoli

There has been an increasing interest in exploring quantities associated with quantum information at colliders. We perform a detailed analysis describing how to measure the quantum discord in the top anti-top quantum state at the Large…

High Energy Physics - Phenomenology · Physics 2025-03-05 Tao Han , Matthew Low , Navin McGinnis , Shufang Su

We highlight an information-theoretic meaning of quantum discord as the gap between the ac- cessible information and the Holevo bound in the framework of ensemble of quantum states. This complementary relationship implies that a large…

Quantum Physics · Physics 2013-03-21 Yao Yao , Jing-Zheng Huang , Xu-Bo Zou , Zhen-Qiang Yin , Wei Chen , Guang-Can Guo , Zheng-Fu Han

Quantum discord, an information-theoretic quantum correlation measure, can satisfy as well as violate monogamy, for three-party quantum states. We quantify the feature using the concept of discord monogamy score. We find a necessary…

Quantum Physics · Physics 2014-04-21 Manabendra N. Bera , R. Prabhu , Aditi Sen De , Ujjwal Sen

The role played by quantum discord in mixed-state computation is widely debated since, in spite of evidence of its importance in creating quantum advantages, even in the absence of entanglement, there are not direct proofs of its necessity…

Quantum Physics · Physics 2013-08-22 Gian Luca Giorgi

Discord and entanglement characterize two kinds of quantum correlations, and discord captures more correlation than entanglement in the sense that even separable states may have nonzero discord. In this paper, we propose a new kind of…

Quantum Physics · Physics 2015-06-02 Jianwei Xu

Quantum correlations described by quantum discord and one-way quantum deficit can contain ordinary regions with {\em constant} (i.e., universal) optimal measurement angle $0$ or $\pi/2$ with respect to the $z$-axis and regions with a {\em…

Quantum Physics · Physics 2019-04-05 Ekaterina V. Moreva , Marco Gramegna , Mikhail A. Yurischev

Recently, a basis-invariant measure of coherence known as the intrinsic degree of coherence has been established for classical and single-particle quantum states [JOSA B {\bf 36}, 2765 (2019)]. Using the same mathematical construction, in…

Quantum Physics · Physics 2020-03-30 Nilakantha Meher , Abu Saleh Musa Patoary , Girish Kulkarni , Anand K. Jha

We propose a scheme to directly measure the exact value of geometric quantum discord of an arbitrary two-qubit state. We only need to perform the projective measurement in the all anti-symmetric subspace and our scheme is parametrically…

Quantum Physics · Physics 2012-03-05 Jia-sen Jin , Feng-yang Zhang , Chang-shui Yu , He-shan Song

We perform an experimental investigation of Quantum Discord with Spin-Orbit X-states. These states are prepared through the incoherent superposition of different laser beans, where a two-level system is encoded in polarization and the…

Quantum Physics · Physics 2023-12-29 V. S. Lamego , D. G. Braga , W. F. Balthazar , J. A. O. Huguenin

Quantum discord (QD) reveals the nonclassical nature of correlations in bipartite quantum states, going beyond the entanglement-separability paradigm. In this article we discuss the suitability of QD in what concern its possible asymmetry…

Quantum Physics · Physics 2015-03-14 J. Maziero , L. C. Celeri , R. M. Serra

We analyze a class of 2-qudit circulant states. They define generalization of well known 2-qubit X-states. We formula the necessary and sufficient criteria for vanishing quantum discord. We illustrate our analysis by an important subclass…

Quantum Physics · Physics 2013-05-06 Bogna Bylicka , Dariusz Chruściński

It is known that quantum discord might experience a sudden transition in its dynamics when calculated for certain Bell-diagonal states (BDS) that are in interaction with their surroundings. We examine this phenomenon known as the sudden…

Quantum Physics · Physics 2013-10-01 João P. G. Pinto , Goktug Karpat , Felipe F. Fanchini

The dynamics of a geometric measure of the quantum discord (GMQD) under decoherence is investigated. We show that the GMQD of a two-qubit state can be alternatively obtained through the singular values of a $3\times4$ matrix whose elements…

Quantum Physics · Physics 2010-09-07 Xiao-Ming Lu , Zheng-Jun Xi , Zhe Sun , Xiaoguang Wang

We have analytically calculated the quantum discord for a system composed of spin-$j$ and spin-1/2 subsystems possessing SU(2) symmetry. We have compared our results with the quantum discord of states having similar symmetries and seen that…

Quantum Physics · Physics 2013-11-05 B. Çakmak , Z. Gedik

Quantum state elimination measurements tell us what states a quantum system does not have. This is different from state discrimination, where one tries to determine what the state of a quantum system is, rather than what it is not. Apart…

Several ways have been proposed in the literature to define a coherence measure based on Tsallis relative entropy. One of them is defined as a distance between a state and a set of incoherent states with Tsallis relative entropy taken as a…

Quantum Physics · Physics 2019-12-12 Anna Vershynina

Analytic quantifiers of the symmetric quantum discord for two-qubit X type states and block-diagonal states and the symmetric measurement induced nonlocality for any two qubit states are established on the basis of the quantum skew…

Quantum Physics · Physics 2019-03-19 Li-qiang Zhang , Si-ren Yang , Chang-shui Yu

We extend the definition of quantum discord as a quantifier of nonClassical correlations in a quantum state to the case where weak measurements are performed on subsystem $A$ of a bipartite system $AB$. The properties of weak discord are…

Quantum Physics · Physics 2015-12-01 Lekshmi S , N Shaji , Anil Shaji
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